Conventional aircraft engine thrust management involves the use of several design processes, such as engine power management in an engine electronic control, thrust limit computer and flight management computer functions of an aircraft information management system, and an aircraft flight manual used for providing aircraft dispatch information. Although all of these processes are connected with three fundamental elements of engine thrust management (i.e. an engine thrust setting target, a commanded engine thrust, and a calculated engine produced thrust), the functional requirements of these processes are unique and do not constitute a system for thrust management on an aircraft.
Conventional engine thrust management is based on either the engine pressure ratio (EPR) or engine rotor speed (N1) parameters. Consequently, conversion back and forth between the three basic thrust elements and EPR or N1 is required. This results in unnecessary duplication and dependency of tasks implemented in each process. Further, implementation of a power management design for different engine types has to be incorporated repeatedly in all three processes. Cockpit display of the thrust setting indication is also different between different aircraft due to different engine types and/or different engine operating modes.
A conventional engine thrust management system is illustrated in FIG. 1 at 10. The conventional system 10 generally comprises an engine power management process 12, an engine electronic control 14 (EEC) located on aircraft engines (not shown), a flight management computer 16 located onboard an aircraft (not shown), and an electronic aircraft flight manual 18 (AFM), located remotely from the aircraft. The engine power management process 12 establishes the maximum rating power setting parameter (PSP) data, which is in terms of EPR or N1, at block 20 using two inputs. The first input, illustrated at block 22, comprises characteristics of the maximum available thrust (FN) and the PSP. The second input, illustrated at block 24, comprises the engine specification thrust or engine required thrust. The data developed at block 20 is duplicated in blocks 25, 29, and 35.
The engine electronic control 14 computes the maximum rated PSP at block 26. The maximum rated PSP pre-defined at block 20 is loaded into the engine electronic control 14 and is used for an engine fuel control parameter at block 28. Thus, by computing the maximum rated PSP at step 26, the EEC is performing a redundant operation with the engine power management process 12, which is a resource consuming process.
The FMC 16 also performs various redundant and resource consuming operations. Specifically, at block 30 the FMC 16 computes the maximum rated PSP, which is also performed at block 26 of the EEC 14. The target PSP at block 30 is also computed at block 36. At block 32 the FMC uses an EPM module to compute the available thrust (FN) and the power setting parameter (PSP), which requires the predetermined data at block 22. At block 34 the FMC computes thrust used in calculations of takeoff V-speeds and aircraft performance predictions, which is a reverse operation with process 12. Thus, the FMC 16 performs numerous redundant calculations, which are wasteful of computing resources and the process 12 must be completed prior to the development of the FMC 16.
The AFM 18 computes the required engine thrust at block 36. At block 38, the AFM 18 includes an EPM module that calculates the maximum available thrust FN and the power setting parameter PSP. Thus, block 38 performs the same operations as are performed at block 32 of the FMC 16 and also requires the pre-determined data block 22. At block 40 the AFM 18 computes the maximum rated PSP and the setting target PSP. Thus, the operations of blocks 26, 30, and 40 are redundant. At block 42, the AFM 18 computes thrust used in calculation of takeoff V-speeds, which is a reversed operation with process 12. The AFM 18 performs numerous redundant calculations, wasteful of computing resources and the process at block 12 must be completed prior to development of the AFM 18.
Thus, there is generally a need for an engine thrust management system that improves aircraft development flow time and aircraft performance capabilities. In particular, there is a need for an engine thrust management architecture that aligns the requirements and eliminates unnecessary redundant tasks across the three main components of engine thrust management. There is also a need for providing a common thrust setting indication that supports the common cockpit display concept.